Draft gear



G. E. DATH Oct. 17, 1944.

DRAF GEAR Filed Oct. 18, 194

Patented Oct. 17, 1944 UNITED STATES PATENT OFFICE DRAFT GEAR George E. Dath, Chicago, 111., assignor to W. H.

Miner, Inc., Chicago, 111., a corporation of Delaware 9 Claims.

This invention relates to improvements in draft gears for railway cars.

One object of the invention is to provide a railway draft gear, especially designed for absorbing shocks produced by a pulling or draft action applied to the coupler or drawbar of a railway car,

A further object of the invention is to provide a railway draft gear of the character indicated in the preceding paragraph comprising a drawbar and a friction shock absorbing mechanism actuated by the drawbar to cushion pulling shocks, wherein the friction shock absorbing mechanism includes a friction casing, friction shoes slidable Within the casing, a combined wedge and spring follower having wedging engagement with the shoes, a spring within the casing opposing inward movement of the shoes, and a pressure transmitting block actuated by the drawbar and engaging the shoes to move the same inwardly against the spring resisted wedge, the pressure transmitting block being anchored to the shoes and holding the latter spread apart and in position to engage limiting shoulders on the casing to restrict both inward and outward movement of the shoes.

A still further object of the invention is to provide a friction shock absorbing mechanism as set forth in the preceding paragraph wherein the casing is open at one end and has limiting shoulders at said open end, and the spring resistance, combined wedge and spring follower, and friction shoes are all insertable through said open end of the casing in assembling the mechanism, the shoes being rockingly displaceable toward the central longitudinal aXis of the casing to clear the limiting shoulders of the latter in being inserted through the open end thereof and being spread apart in position to engage said casing shoulders jointly by the pressure transmitting block and the spring backed combined wedge and spring follower.

Other objects of the invention will more clearly appear from the description and claims hereinafter following.

In the drawing forming a part of this specification, Figure 1 is a longitudinal sectional view, through the underframe structure of a railway car, at one end thereof, illustrating my improvements in connection therewith. Figure 2 is an end elevational view, on an enlarged scale, of the structure shown in Figure 1, looking from right to left in said figure, the underframe structure of the car being omitted. Figure 3 is a vertical sectional view, corresponding substantially to the line 33 of Figure 2. Figure 4 is a view, similar to Figure 2, illustrating the manner of assembling the parts of the friction shock absorbing unit. Figure 5 is a view, similar to Figure 3, illustrating the manner of assembling the parts of the friction shock absorbing unit.

In said drawing, Ill indicates the usual end sill of the car underframe structure, and 11 one of the center sills. As will be understood by those skilled in this art, the usual underframe structure comprises two spaced center sills and these are fixed at their front ends to the end sill. Rearwardly or inwardly of the end sill, the underframe structure has a transverse connecting member I2 which extends between the two sills from one to the other, and has its opposite ends fixed thereto. The member 12 serves as the front stop of the draft rigging of the car and is reinforced by a heavy plate 13 on the inner side thereof, which is preferably welded thereto. The end sill l0 and the member 12 are of channelshaped cross section and are connected by top and bottom plates 14 and 14, which are secured to the top and bottom flanges of said channel members. The drawbar of the car, which is indicated by 15, is of the type having a coupling hook at the outer end thereof for engagement with the coupling means of an adjacent car. The drawbar 15 has an enlarged head 16 at the outer end having the hook formed thereon. The shank 11 of the drawbar 15, which extends rear- Wardly from the head, is of cylindrical cross section, that is, in the form of a cylindrical bar or shaft. The usual nut 18 is threaded on the rear end of the shank IT. The drawbar I5 is accommodated for lengthwise sliding movement in aligned openings l9 and 20 in the end sill I0 and connecting member 12l3. The head I6 of the drawbar is reduced in size at the rear end thereof where it joins the cylindrical shank l1, thereby providing top and bottom shoulders 21-21 adapted to engage the front face of the end sill I0 and limit inward movement of the drawbar.

My improved shock absorber, as shown in the drawing, comprises broadly a friction casing A, a combined wedge and spring follower B, six friction shoes CC, a spring resistance D, and a pressure transmitting block E.

As shown in Figure 1, the friction unit comprising the casing A, combined wedge and spring follower B, shoes C--C, spring D, and pressure transmitting block E is disposed between the draft or center sills of the car in abutment with the front stop |2l3. The shank 11 of the drawbar 15 extends through the unit and actuates the same in draft action, as hereinafter pointed out.

The friction casing A is in the form of a shell of hexagonal transverse cros section, open at one end, and closed at the other end by a transverse wall 22. As shown in Figure 1, the closed end of the casing A bears on the front stop l2l3 of the underframe of the car. The open end of the casing is thus presented at the rear or inner end of the draft rigging. The side walls of the casing, which are indicated by 23-23, are thickened at the open end of the casing, a indicated at 24, and present six flat interior friction surfaces 2525, thereby providing a friction shell portion 26 at the open end of the casing.

At the open end, the hexagonal casing is provided with a laterally inturned, continuous stop flange 21 which is rounded out on the inner side to provide a concave wall portion 28 merging with the friction surfaces of the shell 26. Spaced inwardly from the stop flange 21, or at the inner end of the shell 26, the side walls of the casing are provided with an inwardly extending, annular rib 29 forming a stop shoulder to limit inward movement of the friction shoes.'

The combined wedge and spring follower B is in the form of a heavy, flat plate having six outwardly converging, flat wedge faces 3939 arranged symmetrically about the central longitudinal axis of the mechanism. The plate B is provided with a central opening 3| therethrough adapted to freely accommodate the shank ll of the drawbar l therein.

The friction shoes C, which are six in number, are arranged symmetrically about the axis of the mechanism and cooperate respectively with the six interior friction surfaces 25-25 of the shell 26, each shoe having a flat friction surface 32 on the outer side thereof slidingly engaging one of the surfaces 25, At the inner end each shoe has a fiat wedge face 33 correspondingly inclined to and engaging one of the wedge faces 36 of the combined wedge and spring follower B. At the forward end thereof, the outer side of each shoe is rounded off, as indicated at 34, to fit the concavity of the wall portion 28 of the flange 2'! of the casing. On the inner side, each shoe is provided with a concave bearing seat 35 for a purpose hereinafter described.

The pressure transmitting block E is of hexagonal, transverse cross section and is provided with a transversely extending, outwardly projecting, rounded bearing rib or bead 36 at the inner end of each side face thereof. The ribs 36 are seated in the seats 35 of the shoes C and lock the shoes to the pressure transmitting block. The ribs 36 and seats 35 also form bearing means on which the shoes may be rocked or tilted in assembling the mechanism. The block E is pro vided with a central opening 3! therethrough adapted to freely accommodate the coupler shank for movement, the opening 3'! being countersunk at the outer side of the block, as indicated at 38, to accommodate the nut l8.

The spring resistance D comprises inner and outer coils surrounding the coupler shank II and having their opposite ends bearing respectively on the end wall 22 of the casing and the combined wedge and spring follower B.

A clearly shown in Figures 1 and 2, the shank ll of the drawbar extends through the casing A of the mechanism, the wall 22 of the casing being provided with a central opening 39 therethrough to accommodate the shank of the drawbar. The drawbar shank extends through the opening 39, the inner coil of the spring, the opening 3! of the combined wedge and spring follower B, and the opening 31 of the block E, and is anchored to the latter by the nut l8 accommodated in the seat 38 and shouldered against the bottom of said seat. The nut I8 is preferably secured against accidental removal by a cotter pin 46 extending through the end of the drawbar shank.

In assembling the mechanism, the spring resistance D and the combined wedge and spring follower B are first inserted within the casing A. The spring follower is then pushed inwardly to the position shown in Figure 5 by means of a tool 4| in the form of a bar having pivoted fingers 4242 provided with notches 43-43 adapted to engage over the edge of the wall of the opening 3| of the combined wedge and follower. The shoes CC are then placed within the casing in approximately the position shown in Figure 5 and the pressure transmitting block E, which has previously been disposed on the bar 4 I, i then pushed inwardly to the position shown in Figure 5, bringing the beads 36 thereof into operative engagement with the seats 35 of the shoes C. The shoes are then rocked on the beads or ribs 36 to the position shown in Figure 3, and the tool is withdrawn from engagement with the combined wedge and spring follower 'B, permitting the spring resistance D to expand and force the combined Wedge and follower against the wedge faces of the shoes, as clearly shown in Figure 3. The parts are thus held assembled with the pressure transmitting block E locked to the shoes, and the front ends of the shoes abutting the curved wall portion 28 of the stop flange 21 of the casing.

The assembled friction shock absorbing mechanism or unit is then applied to the car, as shown in Figure 1, with the closed end thereof abutting the stop |2l3 of the underframe structure, the shank ll of the drawbar I5 extending through the unit, and the nut l8 of the drawbar bearing on the rear of the pressure transmitting block E.

In the operation of the mechanism, when a pulling force is applied to the drawbar, the pressure transmitting block B will be pulled inwardly of the casing in unison with the drawbar, thereby forcing the shoes inwardly of the casing against the spring resisted combined wedge and spring follower B. Due to wedging engagement between the wedge faces 33 of the shoes CC and the' wedge faces 30 of the combined Wedge and spring follower B, the shoes are spread apart into intimate frictional contact with the friction surfaces of the casing, thus setting up the required frictional resistance during inward movement of the shoes. When the actuating force is reduced, the spring resistance D restores all of the parts to normal position, outward movement of th shoes CC being limited by engagement of the rounded front ends thereof with the stop flange 21 of the casing.

I have herein shown and described what I now consider the preferred manner of carrying out my invention, but the same is merely illustrative and I contemplate all changes and modifications that come within the scope of the claims appended hereto.

I claim:

1. In a railway draft rigging for a railway car having a front stop, the combination with a friction casin having one end closed and the other end open, said closed end bearing on the front stop of the car; of friction shoes having sliding engagement with the interior walls of said casing; a combined wedge and spring follower member in wedging engagement with the inner ends of the shoes; Spring means opposing inward movement of said member; a block having looking engagement with the shoes; spaced inner and outer stops on the casing for limiting inward and outward movement of said shoes; and a drawbar extending through said casing, spring means, member and block and having shouldered engagement with the latter to pull the same inwardly of the casing in draft.

2. In a railway draft rigging for a railway car having a front stop, the combination with a friction casing open at one end and closed at the other end, said last named end bearing on said front stop of the car; of friction shoes having sliding engagement with the interior walls of said casing; a wedge block and spring follower member having wedging engagement with the shoes; spaced inner and outer stops on the inside of the casing limiting inward and outward movement of said shoes; a spring resistance within said casing comprising two coils opposing inward movement of said member; a pressure transmitting block between said shoes and having ribs seated in grooves in said shoes for locking the shoes to said block; and a drawbar extending through said casing, member and block and having shouldered engagement with the latter to pull the same inwardly of the casing in draft.

3. In a friction shock absorbing mechanism, the combination with a friction casing open at one end, said casing having longitudinally extending, interior friction surfaces at said open end; of a central, combined wedge, and spring follower member; a plurality of friction shoes having sliding frictional engagement with the friction surfaces of the casing and wedging engagement with said member; a pressure transmitting block between said shoes having laterally projectin ribs engaged in seats in said shoes to lock the shoes to said block; pring resistance means yieldingly opposing inward movement of said member; and inner stop means on said casing with which the shoes are engageable to limit inward movement of the latter.

4. In a friction shock absorbing mechanism, the combination with a friction casing open at one end, said casing having interior friction surfaces at said open end; of a laterally, inwardly extending stop flange at the open end of the casing having a concave bearing seat on the inner side thereof; a plurality of friction shoes in sliding engagement with the friction surfaces of the casing, said shoes having wedge faces at the inner ends and rounded faces at the outer ends engageable with the seats of said flange to limit outward movement of the shoes; a spring follower having wedge faces engaging the wedge faces of the shoes; spring means within the easing opposing inward movement of the spring follower; and a pressure transmitting member between said shoes adapted to receive the actuating force, said member being interlocked with the shoes to actuate the latter.

5. In a friction shock absorbing mechanism, the combination with a friction casing open at one end, said casing having interior friction surfaces at said open end; of a laterally, inwardly extending stopflange at the open end of the easing having a concave bearing seat on the inner side thereof; a plurality of friction shoes in sliding engagement with the friction surfaces of the casing, said shoes having wedge faces at the inner ends and rounded faces at the outer ends engageable with the seats of said flange to limit outward movement of the shoes; a spring follower having wedge faces engaging the wedge faces of the shoes; spring means within the casing opposing inward movement of the spring follower; and a pressure transmitting member between said shoes adapted to receive the actuating force, said member and shoes having interengaging ribs and grooves locking the shoes to said member.

6. In a friction shock absorbing mechanism, the combination with a friction casing open at one end, said casing having a plurality of flat, interior friction surfaces at said open end; of a laterally, inwardly projecting stop flange at the outer end of each friction surface having a con'cavely curved bearing surface on the inner side thereof; a plurality of friction shoes in sliding frictional engagement with the friction surfaces of the casing, each shoe having a wedge face at the inner end thereof and a rounded bearing face at the outer end thereof engageable with the curved surface of said flange to limit outward movement of said shoe, each shoe having a concave seat on the inner side thereof; a pressure transmitting block adapted to receive the actuating force, said block having a plurality of transversely extending, projecting, rounded ribs interlocked with the seats of the shoes; a combined wedge and spring follower having wedge faces in wedging engagement with the wedge faces of the shoes; and a spring within the easing opposing inward movement of the combined wedge and spring follower.

7. In a friction shock absorbing mechanism, the combination with a friction casing of hexagonal, interior cross section having six interior, inwardly extending, flat friction surfaces; of a laterally, inwardly projecting stop flange at the outer end of each friction surface having a concavely curved bearing surface on the inner side thereof merging with said friction surfaces; six friction shoes in sliding frictional engagement with the friction surfaces of the casing, each shoe having a wedge face at the inner end thereof and a rounded bearing face at the outer end engag'eable with the curved surface of said flange to limit outward movement of said shoe, each shoe having a concave, transversely extending groove on the inner side thereof; a hexagonal pressure transmitting block adapted to receive the actuating force, said block being disposed between said shoes and having a plurality of transversely extending, laterally projecting, rounded ribs on each of the six sides thereof engaging respectively in the grooves of the respective shoes to lock the block to the shoes; a combined wedge and spring follower having six wedge faces in hexagonal arrangement engaging the wedge faces of the shoes respectively; and spring means within the casing yieldingly opposing inward movement of the combined wedge and spring follower.

8. In a friction shock absorbing mechanism, the combination with a friction casing open at one end, said casing having a plurality of flat, interior friction surfaces at said open end; of a laterally, inwardly projecting stop flange at the outer end of each friction surface having a concavely curved bearing surface on the inner side thereof; a plurality of friction shoes in sliding frictional engagement with the friction surfaces of the casing, each shoe having a Wedge face at the inner end thereof and a rounded bearing face at the outer end thereof engageable with the curved surface of said flange to limit outward movement of said shoe, each shoe having a concave seat on the inner side thereof; a pressure transmitting block adapted to receive the actuating force, said block having a plurality of transversely extending, projecting, rounded ribs interlocked with the seats of the shoes, said shoes having sliding rotary engagement on said curved surfaces of said flange to permit engagement of the ribs of the pressure transmitting member with the seats of said shoes in assembling the mechanism; a combined Wedge and spring follower having wedge faces in wedging engagement with the wedge faces of the shoes; and a spring within the casing opposing inward movement of the combined wedge and spring follower.

9. In a friction shock absorbing mechanism,

the combination with a friction casing of hexagonal, interior cross section having six interior, inwardly extending, fiat friction surfaces; of a laterally, inwardly projecting stop flange at the outer end of each friction surface having a concavely curved bearing surface on the inner side thereof merging with said friction surfaces; six friction shoes in sliding frictional engagement with the friction surfaces of the casing, each shoe having a wedge face at the inner end thereof and a rounded bearing face at the outer end engageable with the curved surface of said flange to limit outward movement of said shoe, each shoe having a concave, transversely extending groove on the inner side thereof; a hexagonal pressure transmitting block adapted to receive the actuating force, said block being disposed between said shoes and having a plurality of transversely extending, laterally projecting, rounded ribs on each of the six sides thereof engaging respectively in the grooves of the respective shoes to lock the block to the shoes, said shoes having sliding rotary engagement on said curved surfaces to permit inward rocking displacement of the inner ends of said shoes toward the central longitudinal axis of the mechanism to facilitate engagement of the ribs of the pressure transmitting member Within the grooves of the shoes in assembling the mechanism; a combined Wedge and spring follower having six wedge faces in hexagonal arrangement engaging the wedge faces of the shoes respectively; and spring means within the casing yieldingly opposing inward movement of the combined wedge and spring follower.

GEORGE E. DATH. 

